Oxytocin IV infusion to investigate peripheral action on heat pain and vibratory perception in healthy volunteers

Chronic pain remains a significant global health burden, often characterized by complex mechanisms and inadequate treatment options. Traditional analgesics frequently carry risks of dependence or severe side effects, driving the search for novel, safer therapeutic targets. Oxytocin, a neuropeptide traditionally associated with social bonding and parturition, has garnered increasing interest for its potential role in pain modulation. While much research has focused on its central effects via intranasal administration, understanding the direct peripheral actions of oxytocin on sensory processing is critical. This study aims to elucidate how systemically administered oxytocin influences peripheral pain and sensory thresholds, providing insights into its potential as a non-opioid analgesic and informing targeted drug development strategies.

This randomized, blinded, crossover study enrolled 11 healthy volunteers to meticulously investigate the peripheral effects of intravenously administered oxytocin versus a placebo. Each participant underwent two separate study visits, receiving either an oxytocin IV infusion or an inactive solution (placebo) in a randomized, double-blind fashion. Following IV catheter placement, a battery of sensory tests was performed. Pain perception was assessed using a thermal probe, which heated the skin to a noxious 116.6 degrees Fahrenheit for 30 seconds, with participants providing subjective pain scores on a 0-10 visual analog scale. Additionally, vibratory perception was measured by applying a vibratory stimulus to the forearm, initiated at a 1 kHz frequency and progressively decreased at a rate of 25 Hz/sec until the participant first detected the vibration, establishing a detection threshold.